She didn't "emerge" until after the impeachment trial. That is to say she didn't go public until after the impeachmennt trial.
However, she was on record well before that. Her story was part of the evidence that was accumulated by the investigators and, because of its delicate nature, was kept under lock and key in a capitol office. All the Representatives and Senators were invited to review this evidence, but few actually did. I don't think a single Democrat requested access to the room.
Those who did review the evidence expressed the appalling nature of numerous testimonies concerning Bill Clinton's predatory behavior.
So, yes, you are correct in your recollection. The Washington Post is clearly trying to marginalize Juanita Broaddrick's testimony.
NBC interviewed Broaddrick on January 20, 1999, but decided to broadcast it until February 24, 1999, right after Clinton impeachment trial.
https://factreal.wordpress.com/2012/09/06/bill-clintons-victim-juanita-broaddrick-said-clinton-raped-her-videos/
The information was in a room for viewing. It likely changed a few GOP minds in the House, and they voted in favor of the Articles of Impeachment.